This invention relates generally to drive assemblies for washing machines, and, more particularly, to a brake cam actuator assembly for reducing noise in an agitate cycle of a washing machine.
One type of washing machine includes a wrap spring clutch that couples a brake cam actuator to a rotationally driven transmission pulley hub to execute an agitate portion of a washing machine cycle. See, for example, U.S. Pat. No. 4,283,928. The brake cam actuator operates to engage or disengage a brake that either prevents or allows, respectively, rotation of a clothes basket inside the machine. This particular construction, however, has proven disadvantageous in at least two aspects.
First, the assembly is susceptible to imperfections in the ends of the transmission pulley hub and brake cam actuator that are interfaced within the wrap spring clutch. Burrs and other imperfections on the surfaces may interfere as the transmission pulley hub and brake cam actuator are rotated with respect to one another, causing a high incidence of knocking noise in the agitate portion of a washer cycle. Factory rework of such machines and customer returns of defective units are contributing to an increased manufacturing cost of the machines.
Second, the brake cam actuator and transmission pulley hub typically form a sealing surface. Normal or expected fluid leaks, such as oil leaks, cannot penetrate the seal and therefore flow toward an opposite end of the brake cam actuator body and contaminate a cam surface of the brake cam actuator. Oil migrating from the cam surface of the brake cam actuator can further contaminate the friction brake surface. The contamination adversely affects operation of the brake, causing the brake to stick and/or slip, and producing squeaking noises in the agitate portion of the machine cycle.
Accordingly, it would be desirable to provide a brake cam actuator assembly that is not as sensitive to imperfections in the interfacing surfaces of the transmission pulley hub and the brake cam actuator and that reduces knocking noise in the agitate portion of a machine cycle. It would also be desirable to provide a brake cam actuator assembly that avoids contamination of the brake cam actuator cam surface friction material to prevent squeaking noise during the agitate portion of the machine cycle.